No abstract

Perlecan is a large heparan sulfate (HS) proteoglycan present in all basement membranes and in some other tissues such as cartilage, and is implicated in cell growth and differentiation. Mice lacking the perlecan gene (Hspg2) have a severe chondrodysplasia with dyssegmental ossification of the spine and show radiographic, clinical and chondro-osseous morphology similar to a lethal autosomal recessive disorder in humans termed dyssegmental dysplasia, Silverman-Handmaker type (DDSH; MIM 224410). Here we report a homozygous, 89-bp duplication in exon 34 of HSPG2 in a pair of siblings with DDSH born to consanguineous parents, and heterozygous point mutations in the 5' donor site of intron 52 and in the middle of exon 73 in a third, unrelated patient, causing skipping of the entire exons 52 and 73 of the HSPG2 transcript, respectively. These mutations are predicted to cause a frameshift, resulting in a truncated protein core. The cartilage matrix from these patients stained poorly with antibody specific for perlecan, but there was staining of intracellular inclusion bodies. Biochemically, truncated perlecan was not secreted by the patient fibroblasts, but was degraded to smaller fragments within the cells. Thus, DDSH is caused by a functional null mutation of HSPG2. Our findings demonstrate the critical role of perlecan in cartilage development.

Between 800,000-1.4 million people in the United States and more than 240 million people worldwide are infected with hepatitis B virus (HBV). Specific to pregnancy, an estimated prevalence of 0.7-0.9% for chronic hepatitis B infection among pregnant women in the United States has been reported, with >25,000 infants at risk for chronic infection born annually to these women. Vertical transmission of HBV from infected mothers to their fetuses or newborns, either in utero or peripartum, remains a major source of perpetuating the reservoir of chronically infected individuals globally. Universal screening for hepatitis B infection during pregnancy has been recommended for many years. Identification of pregnant women with chronic HBV infection through universal screening has had a major impact in decreasing the risk of neonatal infection. The purpose of this document is to aid clinicians in counseling their patients regarding perinatal risks and management options available to pregnant women with hepatitis B infection in the absence of coinfection with HIV. We recommend the following: (1) perform routine screening during pregnancy for HBV infection with maternal HBsAg testing (grade 1A); (2) administer hepatitis B vaccine and HBV immunoglobulin within 12 hours of birth to all newborns of HBsAg-positive mothers or those with unknown or undocumented HBsAg status, regardless of whether maternal antiviral therapy has been given during the pregnancy (grade 1A); (3) In pregnant women with HBV infection, we suggest HBV viral load testing in the third trimester (grade 2B); (4) in pregnant women with HBV infection and viral load >6-8 log 10 copies/mL, HBV-targeted maternal antiviral therapy should be considered for the purpose of decreasing the risk of intrauterine fetal infection (grade 2B); (5) in pregnant women with HBV infection who are candidates for maternal antiviral therapy, we suggest tenofovir as a first-line agent (grade 2B); (6) we recommend that women with HBV infection be encouraged to breast-feed as long as the infant receives immunoprophylaxis at birth (HBV vaccination and hepatitis B immunoglobulin) (grade 1C); (7) for HBV infected women who have an indication for genetic testing, invasive testing (eg amniocentesis or chorionic villus sampling) may be offered-counseling should include the fact that the risk for maternal-fetal transmission may increase with HBV viral load >7 log 10 IU/mL (grade 2C); and (8) we suggest cesarean delivery not be performed for the sole indication for reduction of vertical HBV transmission (grade 2C).

A clinical evaluation of the Amplicor polymerase chain reaction (PCR) assay for the detection of Chlamydia trachomatis in endocervical swabs (Roche Molecular Systems, Branchburg, N.J.) is described. This new clinical system used one-step sample preparation, amplification with biotinylated cryptic plasmid primer pairs (CP24-CP27), uracil-N-glycosylase (AmpErase), and a microtiter format for amplicon capture and detection. Culture with McCoy cells in duplicate 1-dram (3.697-ml) vials with fluorescent immunostaining was the reference system. Endocervical swab samples from 945 women provided 74 culture-positive specimens, of which PCR detected 71. The initial PCR result was positive for 12 additional specimens. Arbitration of the PCR-positive, culture-negative samples by PCR with major outer membrane protein primers, duplicate culture, elementary body direct fluorescent-antibody staining, and DNA extraction PCR showed that all 12 samples were positive for chlamydia, raising the number of truly positive samples from 74 to 86. After arbitration the true sensitivities of PCR and culture were 96.5 and 86%, respectively (P = 0.02). Specificities for both were 100%o. For PCR, the positive and negative predictive values were 100 and 99.7%, respectively. Total test efficiency was 99.7%. A high-test-volume (121 samples) timing study with all items included in the College of American Pathologists work load method indicated that this PCR format took approximately 3 min per sample. Because of the high sensitivity, specificity, and improved ease of handling, we found PCR to be a * Corresponding author. assay and compare it with the 1-dram (3.697-ml) vial McCoy cell culture as the reference method.